Effect of Atomic Oxygen Irradiation on the Properties and Structure of Spacecraft Composite Beta Cloth Film

To study the effects of low Earth orbit environment on the surface properties of polymer matrix composite material, a black Beta cloth film was irradiated by atomic oxygen (AO) in ground-based simulation facility. The structure and properties, including morphology, mass loss, optical properties, and surface composition of the pristine and irradiated films were investigated using scanning electronic microscopy (SEM), high precision microbalance, energy disperse spectroscopy (EDS) and UV/VIS/NIR spectrophotometry. It was found that AO irradiation induced strong erosion of the Teflon resin on sample surface when AO fluence reached 1.85 x 10(22) atoms/cm(2), as evidenced by SEM, EDS and XPS results. The real-time mass loss data show a non-linear relationship between etching and AO fluence. The variation of surface chemical structure and composition lead to bleached surface comparing to pristine black film. The optical properties show some variations of sample emissivity (e(h)) and a substantial decrease of solar absorptance (alpha s) reaching a value of 0.20.